Have you ever experienced a funny happening behind the "magic curtain"?
Back at WDW in '93, I rode a tunnel elevator up with Snow White and Alice who were having a rather "non-Disney" discussion. They were both swearing and talking about that "bitch who plays Little Mermaid", and then Alice even commented how "her breasts can't even fill those seashells". It took everything I could to not fall over laughing. It wouldn't have been nearly as funny had they not been in full costume, about to do meet n' greet.
However, I had a really scarring moment during a character visit to the Disney Store in '91. I had never seen Mickey without his head before, and when I walked in the back to get some stock, the gal portraying him was standing there in everything but the head. I stood there for a moment in shock, and (mostly jokingly) said, "Wow. All my childhood dreams have just been shattered." So, to make matters worse, she put the head back on to get ready to head back out, and then pointed me out to a co-worker and said, "Hey, check it out. I just ruined her childhood dreams". Now, that wasn't nearly as funny, because "Mickey" had just poked fun at me. I haven't forgetten it since.